Sun Microsystems SUN BLADE 150, Service Manual

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Appendix C Functional Description C-7
C.5.2 IChip2 ASIC
IChip2 is a 128-pin thin quad flat package (TQFP) ASIC that functions as an
interrupt concentrator. The interrupt concentrator is capable of processing 11 major
groups of interrupts comprising a total of 48 different interrupt signals at the same
time. The result is a 6-bit encoding, which designates the source of the interrupt. The
IChip2 can prioritize the interrupts based on the round-robin scheduling scheme.
The ASIC also supports three types of interrupts: level high, level low, and pulse
low.
C.5.3 SouthBridge ASIC
The Sun Blade 150 system uses the SouthBridge ASIC, which is a highly integrated
system I/O chip set in a 328-pin, ball grid array (BGA) package. It has the following
integrations:
■
PCI-to-ISA bridge
■
SuperI/O interface
■
PCI IDE controller (UltraDMA 66)
■
AC97-compliant audio interface
■
SMBus (I2C) interface
C.5.3.1 Super I/O Functions
Serial Ports
The serial ports are 16450/16550-compatible UAR with 16-byte FIFOs. The serial
ports have a programmable baud rate generator. See Section A.6, “Modem Setup
Specifications” on page A-6. There is a serial port on the system backpanel. The
second serial port is on the riser card and requires an open PCI card slot for
connection and a custom connector. See
FIGURE C-5
.